{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T13:54:31Z","timestamp":1791381271947,"version":"4.3.3"},"reference-count":12,"publisher":"BMJ","issue":"10","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,9,24]]},"published-print":{"date-parts":[[2026,10]]},"abstract":"<jats:p>Moyamoya disease (MMD) is a progressive cerebrovascular disorder characterised by distal internal carotid artery (ICA) stenosis and compensatory collateral vessel formation. Psychiatric manifestations are rare, particularly in children. We report the case of an early adolescent with previously diagnosed MMD who developed acute-onset psychosis following a febrile illness associated with headache and vomiting. Symptoms included auditory hallucinations, persecutory delusions, emotional lability and Fregoli syndrome, a rare condition in which different strangers are believed to be a familiar person in disguise. Neuroimaging revealed bilateral ICA narrowing with extensive collateral networks. Infectious, autoimmune and metabolic evaluations were unremarkable. The patient underwent superior temporal artery\u2013middle cerebral artery bypass with encephalo-duro-arterio-myo-synangiosis. Psychotic symptoms resolved after surgery, and he returned to baseline functioning within 1\u2009month. This case highlights the importance of considering cerebrovascular aetiologies in abrupt-onset childhood psychosis, even in the absence of major neurological deficits.<\/jats:p>","DOI":"10.1136\/bcr-2025-269907","type":"journal-article","created":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T13:15:19Z","timestamp":1791378919000},"page":"e269907","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Fregoli syndrome in an adolescent with Moyamoya disease"],"prefix":"10.1136","volume":"19","author":[{"given":"Nisha","family":"Rajan","sequence":"first","affiliation":[{"name":"Psychiatry, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-2979-5321","authenticated-orcid":false,"given":"Kiruthika","family":"Asokan","sequence":"additional","affiliation":[{"name":"Psychiatry, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Venkatesh","family":"Karthik","sequence":"additional","affiliation":[{"name":"Paediatrics, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8347-3342","authenticated-orcid":false,"given":"Pediredla","family":"Karunakar","sequence":"additional","affiliation":[{"name":"Paediatrics, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2026,10,7]]},"reference":[{"key":"2026100706151231000_19.10.e269907.1","unstructured":"Swaiman KF . Swaiman\u2019s pediatric neurology: principles and practice. In: Edinburgh London New York Oxford Philadelphia St Louis Sydney Toronto. Elsevier, 2018: 1."},{"key":"2026100706151231000_19.10.e269907.2","doi-asserted-by":"crossref","first-page":"526","DOI":"10.1055\/s-0039-1697246","article-title":"Neurology-Psychiatry Interface: Uncommon Presentation of Moyamoya Disease","volume":"10","author":"Singh","year":"2019","journal-title":"J Neurosci Rural Pract"},{"key":"2026100706151231000_19.10.e269907.3","doi-asserted-by":"crossref","DOI":"10.3389\/fpsyt.2024.1371763","article-title":"Psychiatric manifestations in moyamoya disease: more than a puff of smoke? a systematic review and a case-reports meta-analysis","volume":"15","author":"Saccaro","year":"2024","journal-title":"Front Psychiatry"},{"key":"2026100706151231000_19.10.e269907.4","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1007\/s007870050096","article-title":"Moyamoya disease in a 12-year-old Caucasian boy presenting with acute transient psychosis","volume":"8","author":"Britton","year":"1999","journal-title":"Eur Child Adolesc Psychiatry"},{"key":"2026100706151231000_19.10.e269907.5","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1111\/tops.12108","article-title":"The Fregoli delusion: a disorder of person identification and tracking","volume":"6","author":"Langdon","year":"2014","journal-title":"Top Cogn Sci"},{"key":"2026100706151231000_19.10.e269907.6","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1176\/appi.neuropsych.22010011","article-title":"Neuropsychiatric Features of Fregoli Syndrome: An Individual Patient Meta-Analysis","volume":"35","author":"Teixeira-Dias","year":"2023","journal-title":"JNP"},{"key":"2026100706151231000_19.10.e269907.7","doi-asserted-by":"publisher","DOI":"10.2176\/jns-nmc.2021-0382"},{"key":"2026100706151231000_19.10.e269907.8","doi-asserted-by":"publisher","DOI":"10.1192\/bjp.187.4.366"},{"key":"2026100706151231000_19.10.e269907.9","doi-asserted-by":"publisher","DOI":"10.1136\/archdischild-2017-313386"},{"key":"2026100706151231000_19.10.e269907.10","unstructured":"NICE . Overview | psychosis and schizophrenia in children and young people: recognition and management | guidance | nice. 2013. Available: https:\/\/www.nice.org.uk\/guidance\/cg155 [Accessed 01 May 2026]."},{"key":"2026100706151231000_19.10.e269907.11","article-title":"Fregoli syndrome: an underrecognized risk factor for aggression in treatment settings","volume":"2011","author":"Ashraf","year":"2011","journal-title":"Case Rep Psychiatry"},{"key":"2026100706151231000_19.10.e269907.12","doi-asserted-by":"crossref","first-page":"663","DOI":"10.2147\/NDT.S440975","article-title":"Neuropsychiatric Symptoms of Moyamoya Disease: Considerations for the Clinician","volume":"20","author":"Oakley","year":"2024","journal-title":"NDT"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2025-269907","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T13:15:20Z","timestamp":1791378920000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2025-269907"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10]]},"references-count":12,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2026,10,7]]},"published-print":{"date-parts":[[2026,10]]}},"alternative-id":["10.1136\/bcr-2025-269907"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2025-269907","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10]]}}}